Pressure-equalizer and vacuum-regulating valve.



No. 674,011"). Patented May [4, l90l.

A. A. MCDONALD.

PRESSURE EflUALlZER AND VACUUM REGULATING VALVE.

(Application filed Jan. 22, 190L', (No Model.)

2 Sheets-Sheet I.

Y [/VVENYOR WITNESSES:

Affomey No. 674,0"). Patented May l4, 190i.

A. A. MCDONALD.

PRESSURE EDUALIZEB AND VAD UUM REGULATENG VALVE.

(Application filed Jan. 22, 1901.) No Modl.)

lllllllllllllllllllllllllll "Human! AN l ill I in 4 D z 8 a W A i WJNI/ENTOR 'TNESS vfm/zwfi/llrflwmld,

A/tomey is co, FWTOMTnQ. wuumnrom. a. c.

niiarno status ATET FFICE.

ADAM ALBERT MCDONALD, OF BRUNSVIOK, MARYLAND, ASSIGNOR OF ONE- HALF TOWALPER GRANVILLE MUSGROVE, OF SAME PLACE.

PRESSUHE-EQUAUZER AND VACUUIVl REGULATING VALVE.

SPECIFICATION forming part of Letters Patent No. 674,010, dated May 14,1901.

Application filed January 22, 1901. serial No. 44,451. (No model.)

To all whom it natty concern: D

Be it known that I, ADAM ALBERT MCDON- ALD, a citizen of the UnitedStates, residing at Brunswick, in the county of Frederick and State ofMaryland,- have invented certain new and useful Improvements inPressure-Equalizers and Vacuum-Regulating Valves; and I do herebydeclare the following to be a full, clear, and exact description of theinvention,

IO such as will enable others skilled in the art to which it appertainsto make and use the same.

Myinvention has relation to pressureequalizers adapted to be applied tosteam-cylinders or steam-chests; and it consists in the i5 novelarrangement and construction of its parts, as hereinafter described.

The object of my invention is to provide a simple and effectiveattachment adapted especially to be applied to a locomotive-cylim 2o deror steam-chest, the equalizer being so constructed and attached as toequalize the pressure on both sides of the piston-heads while the steamis out off and the engine is moving and the pistons are reciprocating,

' thus effecting a great saving in wear and tear on the mechanism andpackings and by equalizing the pressures permitting the piston to movefreely, thus not interfering with the speed of the locomotive.

In the accompanying drawings, Figure 1 is a side elevation of a high andlow pressure locomotive-cylinder with the equalizer attached thereto.Fig. 2 is a transverse sectional view of the equalizer cut on onediameter, and Fig. 3 is a transverse sectional view of the equalizer cuton a diameter at right angles to that upon which Fig. 2 is cut.

The equalizer consists of a cylindrical casing 1, having dependent fromits bottom a pocket 2 and extending from its top a dome 3, the dome andthe pocket extending horizontally at a right angle to each other. Theequalizer is mounted on the cylinders 4 4. The bottom of a casing 1 isconnected by 5 means of the pipes 5 5 with the steam-chest. The dome 3is connected by means of the pipes 6 6 to one of the cylinders and bymeans of the pipes 7 7 to the opposite end of said cylinders, the pipes6 and 7 entering the large cylinder on top about five inches from theheads of said cylindento equalize the pressure on the large piston withthe small one. A sliding block 8 is located in the casing, said blockhaving located at its lower end and extending diametrically across thesame a shank 9, said shank entering the pocket 2, said block having atits upper end an extension 10 entering the dome 3, said extension havingan opening 11, adapted to come opposite the upperends of the pipes 6 6and 7 7 when the block 8 is in its lowest position in the casing.

If necessary, when using the engine simple a reducing-valve 12 ofordinary construction could be placed in the connection 13 to prcventtoo high pressure in the low cylinder.

In operation the device Works as follows: When the steam is turned intothe cylinders 4 4, the pressure thereby exerted through the pipes 5 5elevates the block 8, thus causing the solid portion of the extension 10to be interposed between the ends of the pipes 6 6 and 7 7. When it isthe desire to let the locomotive drift, the steam is out 01f from thecylinders, and at the same time pressure being withdrawn from the underside of the block 8 the said block falls into the position as shown inFigs. 2 and 3, thus causing the opening 11 of the extension 10 toregister with the pipe ends 6 6 and 7 7. Thus as the piss- 8o ton-headsreciprocate the steam and air in the cylinders will pass rapidly backand forth through the pipes 6 6 and 7 7, and the piston-heads will at notime be operating against a steam or air cushion in the cylinders. Itwill thus be seen that the device is automatic in its action and willeffect a great saving in wear and tear on the part of the cylinders andpistons.

Having described my invention, what I 0 claim as new, and desire tosecure by Letters Patent, is

l. A device for equalizing the pressure on opposite sides of a pistonwithin a cylinder, consisting of a receptacle having a removable block,connections connecting said receptacle with both ends of the cylindersaid block having an opening and a means adapted to cause said openingto register with the cylinder connections when the steam is off, and ameans I00 adapted to cause a solid portion of said block to beinterposed between the cylinder connections when the steam is on.

2. In combination with a cylinder having a movable piston, apressure-equalizer having connections connecting it with both ends ofthe cylinder, a sliding block having a solid portion adapted to beinterposed between the ends of the said connection when the pressure ison in the cylinder, said solid portion adapted to be withdrawn frominterposition between the connections when the pressure is off.

3. In combination with a cylinder having a moving piston, apressure-equalizer consisting of a casing containing a sliding block,said block having an extension, said casing having a dome adapted toreceive said extension, connections connecting said dome with both endsof the cylinders, a steam connection entering said casing, the partsbeing so arranged that when the steam is on in the cylinder the pressurecauses the block to move and interposes the solid portion of theextension between the ends of the cylinder-head connections, and whenthe steam is off removing said solid portion frorn interposition betweenthe cylinder-head connections.

In testimony whereof I affiX my signature in presence of two witnesses.

ADAM ALBERT MCDONALD. Witnesses:

T. A. RAMEY, L. S. GARDNER.

